Its not the Unity tab, in regedit if you find and remove this: Computer\HKEY_CURRENT_USER\Software\Keiwan Donyagard\Evolution it will reset everything, including losing all your saved creations.
If you have creatures you dont want to lose, edit Computer\HKEY_CURRENT_USER\Software\Keiwan Donyagard\Evolution\NEURAL_NETWORK_SETTINGS_... back to the default setting which is written as 31 30 00